The temperature and pressure at Simla are `15.0^(@)C` and 72.0cm of mercury and at Kalka these are `35.0^(@)C` and 76.0 cm of mercury. Find the ratio of air density at Kalka to the air density at Simla.

Explanation

For Simla
` T_1 =15.0^@C=288K`
` P_1= 72.0 cm of mercury `
For Kalka
` T_2=35.0^@C=308K`
` P_2= 76.0cm of mercury `
From the formula
`PV= (m/M)RT`
` rArr P=(m/V) (1/M)RT`
` rArr P= (d/M) RT `
` rArr d=(PM)/(RT)`
thus
` (d_2/d_1)= (P_2/T_2) xx (T_1/P_1) = (76.0 xx 288)/(308 xx72.0)`
`(d_2/d_1)= .987`